Nelson, who joined HBO Sports in August 2011 as director of programming, will oversee the network's boxing franchise as one of his key responsibilities. He had been serving as vice president of programming for HBO Sports. The Harvard graduate and one-time sportswriter takes on his new responsibilities immediately.

Nelson's appointment was no surprise, as he was personally hired by Michael Lombardo, the president of HBO programming, and has remained close with Lombardo.

It also completes a dramatic overhaul in the department. In addition to Hershman's resignation, Mark Taffet resigned last week. No other hires are expected at this time. Nelson's leadership team at HBO includes Tammy Ross, the longtime vice president of HBO Pay-Per-View; and Jonathan Galst and Peter Mozarsky, both senior vice presidents of business affairs. Rick Bernstein remains the executive producer of HBO Sports.

“Peter Nelson is the ideal choice to spearhead our groundbreaking programming initiatives as well as our commitment to world class boxing, which have made HBO Sports an acclaimed franchise for the network,” Lombardo said. “He has a comprehensive understanding of boxing, a key programming staple for our subscribers for more than four decades. We enjoyed a terrific 2015 season and can’t wait to present the best collection of fighters in the world on our platforms in the new year.”

Nelson will face challenges that his immediate predecessors, Ross Greenburg and Hershman, did not. With the Premier Boxing Champions showing boxing on a near-weekly basis and on free network television, there is competition for fighters as well as the loyalty of the viewers.

Hershman famously banned Golden Boy Promotions fighters from HBO because of its close affiliation with PBC creator Al Haymon. Nelson told Yahoo Sports on Tuesday he is open to working with all promoters.

That is tricky, though, in some cases. On Saturday, WBC light heavyweight champion Adonis Stevenson said on a Showtime broadcast that he met in person in Quebec City with IBF/WBA/WBO champion Sergey Kovalev about a fight in June. That has been a fight that fans have wanted for a long time, but was scuttled when Stevenson left HBO to sign with Showtime.

A thorny problem for Greenburg and Hershman over the years was when the best opponent for a fighter they had under contract was affiliated with Showtime. The battle over which network would air the fight often meant that it didn't happen at all.

It is vital for Nelson to fix that, and he said he is confident he can. He's not necessarily open to sharing such fights with another network unless it is a significant pay-per-view bout like Floyd Mayweather-Manny Pacquiao or Lennox Lewis-Mike Tyson.

"When there has been a once-in-a-generation fight to be made is when you've seen a dual-type telecast," Nelson said. "In this situation, what we're committed to is seeing Sergey Kovalev's career arc go in the deepest, richest direction it can. To that end, the fights that can get made that are going to be of greatest adversity for him and greatest challenge to him, those are the types of fights he wants. And those are the types of fighters we want.

"So to the extent that Sergey Kovalev is saying, 'Let's get this fight made,' that's the extent to which we're rallying behind it and will try to make it happen."

In essence, things likely won't change in that regard. But Nelson is the man who in his previous role spearheaded the idea of putting pound-for-pound king Roman "Chocolatito" Gonzalez, the flyweight champion, on HBO even though the network historically had ignored those lighter weight divisions.

He is not only open to but aggressively acting toward making the best fights regardless of weight class, so a potentially epic flyweight rematch between Gonzalez and Juan Francisco Estrada could be made and broadcast on HBO.

"Our boxing fans are sophisticated viewers, and they care about the quality of the fighters themselves," Nelson said. "Size shouldn't be a delineating factor as to whether or not a figher can appear on a premium platform like HBO. In Roman Gonzalez's case, he has a lot of momentum behind him with recognition as one of the top pound-for-pound fighters – the top pound-for-pound fighter on many lists – and I think that kind of [talent] deserves to be seen by as wide a public as possible."

Yahoo Sports asked Nelson if he would consider MMA shows. Greenburg was deep in discussions with the UFC about a broadcast deal about 10 years ago, but the talks stalled near the finish line. Hershman, despite having had success with MMA when he was in charge at Showtime, never seriously considered MMA during his tenure at HBO.

And Nelson isn't showing that inclination, either.

"Our commitment right now is to boxing," he said. "That's I think where our greatest institutional history resides and it's where I think a great future burns brightly. And it's what I'm looking forward to digging into both to close out this year and into 2016."